An ecological approach for skill development and performance in soccer goalkeeper training: Empirical evidence and coaching applications.

Ecological approaches in sport consider that athletes adapt to properties of the task and the surrounding environment. Thus, task and environment are key constraints of performance. Yet, the influence of task and environmental constraints on athletes' performance needs empirical examination, especially in sport-specific contexts such as soccer goalkeeping. This study aimed to examine if and how task and environmental constraints influenced goalkeepers (GKs') performances. We monitored performance coefficients of two professional female GKs across 13 training tasks that varied based on 9 constraints, referring to both interactions among athletes and properties of the surrounding landscape. Results showed that constraints explain ~ 47% of the observed variability in GKs' performances. Numerical complexity (i.e., the potential interactions between athletes) showed a major influence on performance, which indicates that number of interactions among athletes may constrain GKs' perceived opportunities for action. Field dimensions and landscape representativity (including elements such as penalty area(s), target goal(s) and constraints for shooting) showed positive relationships with performance, supporting that training designs retaining closer proximity to the game may benefit GKs' performances. Overall, results supported that athlete-environment couplings could be understood as a multifactorial model and hence, a combination of task constraints are necessary for designing effective learning environments.

Utilizing 2D-region-based CNNs for automatic dendritic spine detection in 3D live cell imaging.

Dendritic spines are considered a morphological proxy for excitatory synapses, rendering them a target of many different lines of research. Over recent years, it has become possible to simultaneously image large numbers of dendritic spines in 3D volumes of neural tissue. In contrast, currently no automated method for 3D spine detection exists that comes close to the detection performance reached by human experts. However, exploiting such datasets requires new tools for the fully automated detection and analysis of large numbers of spines. Here, we developed an efficient analysis pipeline to detect large numbers of dendritic spines in volumetric fluorescence imaging data acquired by two-photon imaging in vivo. The core of our pipeline is a deep convolutional neural network that was pretrained on a general-purpose image library and then optimized on the spine detection task. This transfer learning approach is data efficient while achieving a high detection precision. To train and validate the model we generated a labeled dataset using five human expert annotators to account for the variability in human spine detection. The pipeline enables fully automated dendritic spine detection reaching a performance slightly below that of the human experts. Our method for spine detection is fast, accurate and robust, and thus well suited for large-scale datasets with thousands of spines. The code is easily applicable to new datasets, achieving high detection performance, even without any retraining or adjustment of model parameters.

Acute lesion extension following pulmonary vein isolation with two novel single shot devices: Pulsed field ablation versus multielectrode radiofrequency balloon.

INTRODUCTION: Pulsed-field ablation (PFA) and the multielectrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent. We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury. METHODS: PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multielectrode RFB (HELIOSTAR). Before and after PVI high-density mapping with CARTO 3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping and serum concentrations of high-sensitive Troponin I were quantified by immunoassay. RESULTS: Sixty patients undergoing PVI by PFA (n = 28, age 69 ± 12 year, 60% males, 39.3% persistent atrial fibrillation [AF]) or RFB (n = 32, age 65 ± 13 year, 53% males, 21.9% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses was 34.2 ± 4.5 and mean number RFB applications was 8.5 ± 3 per patient. Total posterior ablation area was significantly larger in PFA (20.7 ± 7.7 cm²) than in RFB (7.1 ± 2.09 cm²; p < .001). Accordingly, posterior ablation area for each PV resulted in larger lesions after PFA versus RFB (LSPV 5.2 ± 2.7 vs. 1.9 ± 0.8 cm², LIPV 5.5 ± 2.3 vs. 1.9 ± 0.8 cm², RSPV 4.7 ± 1.9 vs. 1.6 ± 0.5 cm², RIPV 5.3 ± 2.1 vs. 1.6 ± 0.7 cm,² respectively; p < .001). In a subset of 38 patients, increase of hsTropI was higher after PFA (625 ± 138 pg/mL, n = 28) versus RFB (148 ± 36 pg/mL, n = 10; p = .049) supporting the evidence of larger lesion extent by PFA. CONCLUSION: PFA delivers larger acute lesion areas and higher troponin release upon successful PVI than multielectrode RFB-based PVI in this single-center series.

Principal component analysis suggests multiple dimensions of memory inhibition that are differentially affected by age.

Background: Cognitive inhibition is among the executive functions that decline early in the course of normal aging. Failures to be able to inhibit irrelevant information from memory may represent an essential factor of age-associated memory impairment. While a variety of elaborate behavioral tasks have been developed that presumably all index memory inhibition, the extent to which these different tasks measure the same underlying cognitive construct that declines with age has not been well explored. Methods: In the current study, 100 and 75 cognitively healthy younger (n = 71; age = 30.7 ± 5.4 years, 56.7% female) and older (n = 104, age = 69.3 ± 5.9 years, 66.2% female) adults with equivalent educational attainment performed three computer-based memory inhibition tasks: the Retrieval Induced Forgetting task, the Suppress task, and the Directed Forgetting task. We conducted a principal component analysis using scores derived from different components of these tasks to explore whether and how the tasks relate to one another. We further investigated how age, sex and education, along with, in a subsample of the participants, a neuropsychological measure of episodic memory, impacted both the task scores individually, and the principal components derived from the exploratory analysis. Results: We identified 3 distinct sources of variability which represent potentially independent cognitive processes: memory retrieval facilitation, and two memory inhibition processes that distinguished themselves by the degree of volitional initiation of memory suppression. Only the memory retrieval component correlated with a neuropsychologically-derived episodic memory score, and both memory inhibition principal components were age dependent. Conclusion: Our findings provide support for a distinction in memory suppression processes between those 'instructed' to be performed and those which happen without explicit instruction. This distinction adds nuance to the dichotomous classification of controlled vs. automatic inhibitory mechanisms, which have been shown in previous work to vary as a function of the degree of frontal involvement. Our findings further demonstrate that while both of these measures of inhibition were affected by age, the episodic memory component was not, suggesting that inhibitory impairments may precede memory deficits in healthy aging.

What do you hear? The effect of stadium noise on football players' passing performances.

Stadium noise - created by spectators and fans - plays a critical part in the reality of professional sports. Due to a lack of research on the impact of these auditory cues and multimodal environments on motor performance, it is currently unclear how professional athletes experience and perceive stadium noise and how this potentially affects performance in practice. In order to explore the effect of stadium noise on athletes' performance, this paper presents an experimental design using the unique and standardised football training tool known as the "Footbonaut". Specifically, fifteen skilled German football players engaged in a standardised football-specific technical training programme while subjected to four different auditory training conditions; these included both "positive" and "negative" stadium noise conditions, a "baseline" condition providing auditory guidance, and a "no (auditory) cue" condition. Performance data for passing accuracy and passing time were measured for training in each auditory condition. A repeated measures MANOVA revealed a significant main effect for passing time. Specifically, participants showed faster passing times in the baseline compared to the negative and no auditory cue conditions. Findings are presented and discussed from a constraints-led perspective, allied to principles of ecological dynamics and nonlinear pedagogy. Particularly, the use of representative training experiences (including multimodal sensory and emotional information) appears to underline training to refine expert athletes' adaptive coordination of complex motor actions.

Specialist Coaching Integrated into a Department of Methodology in Team Sports Organisations.

With increasing resources in sports organisations being allocated to the development and preparation of individual athletes and sub-groups with specialist performance roles, the work of coaches, specialist (role) coaches and support staff needs to be functionally and coherently integrated. This integration of sport science support and coaching can be administered by staff in a Department of Methodology (DoM). Particularly, in this paper, we propose how specialist coaching can be situated in a DoM, presenting a model advocating effective functioning in high-performance team sports organisations. Using principles of ecological dynamics, we provide a rationale for a functional methodology for the design of practice tasks in a DoM that views learners as wayfinders, self-regulating their way through competitive performance environments. This rationale for athlete self-regulation in practice could improve athlete performance by enhancing problem solving, engagement with constraints of learning designs and supporting better attunement to contextual information abundant in a competitive environment. Finally, by introducing this unified and multidisciplinary DoM, specialist coaches, team coaches and sport science support staff, within the organisational structure, can collaboratively debate and co-design individualised athlete training programmes to enrich skill adaptability and performance functionality. To underline these contentions, three high-performance sport case studies from Australian Football: goalkeeping in Association Football and Rugby League are presented.

When and How to Provide Feedback and Instructions to Athletes?-How Sport Psychology and Pedagogy Insights Can Improve Coaching Interventions to Enhance Self-Regulation in Training.

In specialist sports coaching, the type and manner of augmented information that the coach chooses to use in communicating and training with individual athletes can have a significant impact on skill development and performance. Informed by insights from psychology, pedagogy, and sport science, this position paper presents a practitioner-based approach in response to the overarching question: When, why, and how could coaches provide information to athletes during coaching interventions? In an ecological dynamics rationale, practice is seen as a search for functional performance solutions, and augmented feedback is outlined as instructional constraints to guide athletes' self-regulation of action in practice. Using the exemplar of team sports, we present a Skill Training Communication Model for practical application in the context of the role of a specialist coach, using a constraints-led approach (CLA). Further based on principles of a non-linear pedagogy and using the recently introduced Periodization of Skill Training (PoST) framework, the proposed model aims to support practitioners' understanding of the pedagogical constraints of feedback and instruction during practice. In detail, the PoST framework's three skill development and training stages work to (1) directly impact constraint manipulations in practice designs and (2) indirectly affect coaches' choices of external (coach-induced) information. In turn, these guide practitioners on how and when to apply different verbal instruction methodologies and aim to support the design of effective skill learning environments. Finally, several practical guidelines in regard to sports coaches' feedback and instruction processes are proposed.

Association Between Cognitive Test Performance and Subjective Cognitive Decline in a Diverse Cohort of Older Adults: Findings From the KHANDLE Study.

BACKGROUND: Subjective cognitive decline (SCD) may represent a low-burden indicator of dementia risk. The value of SCD as a proxy marker, however, depends on the consistency of associations between subjective and objective cognitive measures across sociodemographic and psychological factors. METHODS: We evaluated baseline data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study (n=1615). SCD was measured using the 12-item Everyday Cognition (ECog) scale. Using linear regression models with interaction terms, we evaluated 6 potential modifiers (age, sex, race/ethnicity, educational attainment, family history of dementia, and depressive symptoms) of the association between cognitive performance (episodic memory, executive function) and SCD. RESULTS: Lower episodic memory and executive function scores were associated with higher log(ECog scores) (more SCD). Older age and elevated depressive symptoms were associated with higher log(ECog scores). Age (interaction P=0.002) and education (interaction P=0.01) modified the association between executive function and log(ECog scores). Specifically, associations between executive function and log(ECog scores) were stronger among participants with more education and less pronounced among older participants. CONCLUSIONS: The association between cognitive performance and log(ECog scores) differed little across sociodemographic and psychological factors. SCD as measured by the ECog may be a valuable proxy for cognitive performance in diverse older adults.

How does the modern football goalkeeper train? - An exploration of expert goalkeeper coaches' skill training approaches.

The football goalkeeper position arguably represents a unique role within the team sport. Despite its highly complex skill demands, research on football goalkeeping has only sporadically examined the position within isolated and limited parameters. In particular, there is limited literature on "modern" skill acquisition training methods and approaches within the field of goalkeeper training. In a cross-cultural study with fifteen expert goalkeeper coaches, researchers here examined the overarching research question of "how does the modern football goalkeeper train?". Semi-structured interviews explored expert coaches' views on critical skills for performance in goalkeeping and the training approaches used to develop these critical skills. Results indicate that four skill sets are considered essential by goalkeeper coaches, these are: decision-making skills, athleticism, mentality, and technical skills. In terms of developing these skills in goalkeeper-specific training, the majority of expert coaches apply a similar microstructure to training sessions. This structure involves a steady progression from simple to complex training tasks, where for large parts, isolated technical training appears to be prioritised over a holistic training approach that integrates technical skills and perceptual-cognitive components (e.g., decision making). Scientific and practical recommendations for researchers and practitioners in the field of football goalkeeper coaching are provided.

Skill Training Periodization in "Specialist" Sports Coaching-An Introduction of the "PoST" Framework for Skill Development.

Across sports and movement science, training periodization has been recognized as key for athlete development and performance. While periodization with regard to physiology has a proven history, the structuring and periodization of motor learning and skill development is seemingly less researched and practiced. Despite the existence of numerous theoretical accounts underpinning skill acquisition training and more recently emerging periodization models, a cohesive framework to practically support coaches in the context of "specialist coaching" appears to be needed. The use of "specialist coaches" for individualized, one-on-one or small group trainings displays a growing trend in team ball sports. Despite limiting the replication of game-representative environments (i.e., by constraining the number of involved athletes in training), "specialist coaches" in performance sport constantly aim to achieve marginal gains and refinements in athlete development. In order to support these "specialist coaches" and fill a research gap on skill training periodization, the current paper seeks to review and transfer contemporary skill acquisition training theory (driven by the constraints-led approach) into a practically-applicable "Periodization of Skill Training" framework ("PoST" framework). This framework provides valuable conceptual and practical support for "specialist coaches" in performance sport; which will in turn, enhance, and refine adaptive movement variability for sport skills and manipulate skill training environments (i.e., over the course of macro- and micro-cycles, and for the planning of single training sessions). Practical examples from soccer goalkeeping (i.e., a "specialist coaching" context, often constrained to a small number of players in the training environment) will underline the proposed framework.

High-density waveguide superlattices with low crosstalk.

Silicon photonics holds great promise for low-cost large-scale photonic integration. In its future development, integration density will play an ever-increasing role in a way similar to that witnessed in integrated circuits. Waveguides are perhaps the most ubiquitous component in silicon photonics. As such, the density of waveguide elements is expected to have a crucial influence on the integration density of a silicon photonic chip. A solution to high-density waveguide integration with minimal impact on other performance metrics such as crosstalk remains a vital issue in many applications. Here, we propose a waveguide superlattice and demonstrate advanced superlattice design concepts such as interlacing-recombination that enable high-density waveguide integration at a half-wavelength pitch with low crosstalk. Such waveguide superlattices can potentially lead to significant reduction in on-chip estate for waveguide elements and salient enhancement of performance for important applications, opening up possibilities for half-wavelength-pitch optical-phased arrays and ultra-dense space-division multiplexing.

Structural properties of methanol-water binary mixtures within the quantum cluster equilibrium model.

Density functional theory (B3LYP-D3, M06-2X) has been used to calculate the structures, interaction energies and vibrational frequencies of a set of 93 methanol-water clusters of different type (cubic, ring, spiro, lasso, bicyclic), size and composition. These interaction energies have been used within the framework of the Quantum Cluster Equilibrium Theory (QCE) to calculate cluster populations as well as thermodynamic properties of binary methanol-water mixtures spanning the whole range from pure water to pure methanol. The necessary parameters amf and bxv of the QCE model were obtained by fitting to experimental isobars of MeOH-H2O mixtures with different MeOH content. The cubic and spiro motifs dominate the distribution of methanol-water clusters in the mixtures with a maximum of mixed clusters at x(MeOH) = 0.365. Reasonable agreement with experimental data as well as earlier molecular dynamics simulations was found for excess enthalpies H(E), entropies S(E) as well as Gibbs free energies of mixing G(E). In contrast, heat capacities Cp and C showed only poor agreement with experimental data.

Identification of a B cell-dependent subpopulation of multiple sclerosis by measurements of brain-reactive B cells in the blood.

B cells are increasingly coming into play in the pathogenesis of multiple sclerosis (MS). Here, we screened peripheral blood mononuclear cells (PBMC) from patients with clinically isolated syndrome (CIS), MS, other non-inflammatory neurological, inflammatory neurological or autoimmune diseases, and healthy donors for their B cell reactivity to CNS antigen using the enzyme-linked immunospot technique (ELISPOT) after 96 h of polyclonal stimulation. Our data show that nine of 15 patients with CIS (60.0%) and 53 of 67 patients with definite MS (79.1%) displayed CNS-reactive B cells, compared to none of the control donors. The presence of CNS-reactive B cells in the blood of the majority of patients with MS or at risk to develop MS along with their absence in control subjects suggests that they might be indicative of a B cell-dependent subpopulation of the disease.

Structural optimization for heat detection of DNA thermosequencing platform using finite element analysis.

For the past three decades, Sanger's method has been the primary DNA sequencing technology; however, inherent limitations in cost and complexity have limited its usage in personalized medicine and ecological studies. A new technology called "thermosequencing" can potentially reduce both the cost and complexity of DNA sequencing by using a microfluidic platform [Esfandyarpour, Pease, and Davis, J. Vac. Sci. Technol. B26, 661 (2008)]. To optimize the efficiency of the technology, finite element analysis was used to model the thermosequencing system by simulating the DNA incorporation reaction series and the resulting product concentration and heat production. Different models of the thermosequencing platform were created to simulate the effects of the materials surrounding the system, to optimize the geometry of the system, and to concentrate reaction heat into specific regions for detection in the real system. The resulting concentrations of reaction products were used to calibrate the reaction speed and to design the heat sensors in the thermosequencing technology. We recommend a modified gated structure for the microfluidic detection platform by using control valves and show how this new platform could dramatically improve the detection efficiency.

Comparison of Chirasil-DEX CB as gas chromatographic and ULMO as liquid chromatographic chiral stationary phase for enantioseparation of aryl- and heteroarylcarbinols.

For a broad spectrum of simple chiral alcohols, incorporating a (substituted) (het)aryl building block, enantiomer separation characteristics are reported for both gas chromatography on a Chirasil-DEX phase, and liquid chromatography on an (S,S)-ULMO phase. On this chiral Pirkle-type phase, homochiral enantiomers (mostly R) are eluted first without exception. The elution order R before S appears conserved as a rule also for gas chromatographic separations on Chirasil-DEX, though with some remarkable exceptions indicating a change in the dominant discriminative mechanism. This was shown in the homologous series 1-phenylethanol to 1-phenylhexanol having the point of reversal at C4, while the o-methoxy analogues elute from C1 to C4 already in the reversed order.

Crosslinking of fibrinogen and fibronectin by free radicals: a possible initial step in adhesion formation in osteoarthritis of the temporomandibular joint.

PURPOSE: Adhesion formation in osteoarthritis (OA) of the temporomandibular joint (TMJ) typically results in a sustained limitation of joint movement. We propose the hypothesis that free-radical-mediated crosslinking of proteins underlies this adhesion formation in affected joints. Free radicals may cause oxidative modification of proteins, creating an opportunity for the formation of intramolecular and intermolecular crosslinks via covalent bonds. This may stabilize protein aggregates, rendering them more resistant to degradation. In this study, the free-radical-mediated crosslinking of model proteins (fibrinogen and fibronectin) was investigated to test our hypothesis that free radicals contribute to adhesion formation via this mechanism in OA of the TMJ. MATERIALS AND METHODS: Physiological clot formation of fibrinogen by thrombin and free-radical-induced crosslinking of fibrinogen and of fibronectin were analyzed using spectrophotometric turbidity measurements, light-scattering techniques, polyacrylamide gel electrophoresis (PAGE), and rotary shadowing. RESULTS: Fibrinogen was shown to aggregate after free radical treatment, as detected using turbidity measurements and light-scattering techniques. Using PAGE, fibrinogen as well as fibronectin was shown to degrade under low oxidative stress. Under high oxidative stress, however, fragments from both proteins were found to be covalently crosslinked, resulting in high-molecular-weight protein aggregates. The aggregation was shown to be at random with rotary shadowing. CONCLUSION: The study shows that high oxidative stress contributes to the formation of crosslinked proteins that may serve as an initial scaffolding for the development of adhesions frequently seen in OA of the TMJ.

Absolute configuration in 4-alkyl- and 4-aryl-3,4-dihydro-2(1H)-pyrimidones: a combined theoretical and experimental investigation.

Structural features (orientation of the carboxyl group, ring puckering), electronic absorption, and circular dichroism spectra of 4-alkyl- and 4-aryl-dihydropyrimidones 1-5 are calculated by semiempirical (AM1, INDO/S), ab initio (HF/6-31G, CIS/6-31G, RPA/6-31G), and density functional theory (B3LYP/6-31G) methods. These calculations allow an assignment of the absolute configuration by comparison of simulated and experimental CD spectra. Although the ab initio methods greatly overestimate electronic transition energies, the general appearance of the experimental CD spectra is quite nicely reproduced by these calculations. Thus, comparison of experimental with calculated CD spectra is a reliable tool for the assignment of the absolute configuration. For 4-methyl derivatives 1, the first enantiopure DHPM examples with no additional aromatic substituent, the stereochemistry at C4 provided by the theoretical results is confirmed by X-ray structure determination of the diastereomeric salt 6. Additional support is the consistent HPLC elution order found for all investigated DHPMs on a cellulose-derived chiral stationary phase.

Quantitative structure-enantioselective retention relationships for chromatographic separation of arylalkylcarbinols on Pirkle type chiral stationary phases.

Quantitative structure-retention (QSRR, retention factors log k1 and log k2 for the first and second eluted enantiomer) as well as enantioselective retention relationships (QSERR, separation factor log a) for a series of 42 chiral arylalkylcarbinols on four brush-type chiral stationary phases are derived by multiple linear regression analyses and artificial neuronal network calculations using 2D and 3D molecular descriptors including those obtained by quantum chemical calculations. Separation factors are in addition modeled by the 3D-QSAR method of comparative molecular field analysis (CoMFA). For the retention factors the LUMO energy turns out to be the most important descriptor, whereas for log a it is the hydrophobicity of the analytes. With CoMFA both the steric and electrostatic field are found to be of almost comparable significance.

Nucleophilic substitution by a hydroxide ion at a vinylic carbon: ab initio and density functional theory studies on methoxyethene, 3-methoxypropenal, 2,3-dihydro-4H-pyran-4-one, and 4H-pyran-4-one.

Nucleophilic substitutions by a hydroxide ion at vinylic carbons of methoxyethene (system A), 3-methoxypropenal (system B), 2,3-dihydro-4H-pyran-4-one (system C), and 4H-pyran-4-one (system D) were calculated by Becke's three-parameter hybrid density functional-HF method with the Lee-Yang-Parr correlation functional (B3LYP//B3LYP) and the second-order Møller-Plesset theory (MP2//B3LYP) using the 6-31+G(d) and AUG-cc-pVTZ basis sets. In addition, bulk solvent effects (aqueous solution) were estimated by the polarized continuum (overlapping spheres) model (PCM-B3LYP//B3LYP) and the polarizable conductor PCM model (CosmoPCM-B3LYP//B3LYP). The mechanisms as well as the influence of resonance, cyclic strain, aromatic, and polar effects on the reactivity of the calculated systems were determined. In the gas phase the rate-determining step of nucleophilic vinylic substitutions by a hydroxide ion may be either addition of hydroxide ion at the vinylic carbon (systems A and B) or elimination of the leaving group (systems C and D). In aqueous solution, for all four systems investigated, addition of hydroxide ion at the vinylic carbon is rate determining.

Classical QSAR and comparative molecular field analyses of the host-guest interaction of organic molecules with cyclodextrins.

The application of classical QSAR and molecular modeling analysis using Comparative Molecular Field Analysis (CoMFA) to the complexation of some natural and modified cyclodextrins (CDs) with guest molecules was examined. For 1:1 complexation systems between natural beta-CD, modified alpha-, beta-, and gamma-CD that bear one p-(dimethylamino)benzoyl (DMAB) moiety (DMAB-alpha-, beta-, and gamma-CDs) and guest molecules of widely varying chemical structures and properties, the binding constants of the complexes were successfully fitted using multiple linear regression (MLR) with hydrophobic descriptor log P (the partition coefficient between 1-octanol and water phases) and molecular connectivity indices. A non-linear dependency of binding constants on the zero-th and/or first order molecular connectivity index as a measure of size becomes apparent. The modeling performance of the CoMFA models with steric/electrostatic fields to DMAB-alpha- and beta-CD systems was comparable to those of MLR models. However, statistically significant CoMFA models for gamma-CD systems which have higher conformational flexibility of the ring could not be obtained. The CoMFA models obtained for DMAB-alpha- and beta-CD systems showed that the predominant effects were steric for the DMAB-alpha-CD system and electrostatic for the DMAB-beta-CD system, respectively.